Channel Page – Channel Hardware Category

Enabled Used to Enable/Disable the channel

Channel Mode Sets the channel’s mode of operation:
• TOFD
• Pulse Echo
• Phased Array
Per F-Law Probe Delay Checked when per focal law calibration using the wizard has been completed If manual (theoretical) calibration is
carried out, the box will be
unchecked.
Per F-Law TCG Checked when per focal law Time Corrected Gain using the wizard has been If manual (theoretical) TCG is
completed established, the box will be
unchecked.
TX/RX Control (ToFD/Pulse Echo only)
TX This value sets the TX transducer number The socket to which the probe is
connected
RX This value sets the RX transducer number The socket to which the probe is
connected
Pulse Width
Pulse Width Controls the width of the pulse used to excite the TX transducer according to the
formula ((1 / TX transducer frequency) / 2)
Calculate Opens a dialog box that allows the entry of probe frequency. The software uses
this value to select the appropriate pulse width for the transducer
Hi Pass Filter Shows the value of the Hi-Pass filter. If the display is RED this indicates that an
inappropriate filter has been selected for the transducer frequency To adjust this value, click the filters
If both Hi-Pass & Lo-Pass filter settings are RED, then the filters are crossed i.e. button.
Hi-Pass is set higher than Lo-Pass.
Probe Frequency This field shows the appropriate transducer frequency for the selected pulse
width. As the pulse width value is modified with the Up/Down keys, this field is
updated.
Lo Pass Filter Shows the value of the Lo-Pass filter. If the display is RED this indicates that an To adjust this value, click the filters
inappropriate filter has been selected for the transducer frequency. button.
Digitiser Control
Bits per Sample Sets the bit rate at 8 or 14 bits. 8 bit: signal will saturate at 100%
FSH
14 bit: signal will saturate at 400%
FSH
Sample Rate Sets the digitiser frequency along with the Master Clock, which is set in the
Global page.
Averaging Controls averaging for the channel. For Pulse Echo channels, averaging is Signal averaging is software
performed before peak detection. This gives greatly improved performance for technique used to reduce random
noise. Most often used in ToFD
detecting very low amplitude signals.
applications.
Amplifier Control
Gain Controls the channel’s gain.
+6dB / -6dB Increase / Decreases gain in 6dB steps
T.C.G. Curve Used to select an amplitude correction curve for the channel. The amplitude correction is
displayed as a Time Corrected Gain
curve (TCG).
See: Time Corrected Gain (TCG) in
Appendix A for guidance on setting
up TCG and Appendix C for detailed
instructions.
Note: this control is used when the
curve is established manually
(theoretical). For ‘per focal law’
TCG, use the wizard.
Acquisition Gain (Pulse Echo/Phased Array only)
Enabled Acquisition Gain allows the user to define an amount of gain that will be added Also known as transfer
to the base gain during data acquisition. This feature satisfies the requirement correction.
of certain inspection procedures to apply additional sensitivity during acquisition.
Gain Increase Additional gain to be applied during data collection. This additional gain may be
removed during analysis.
 Auto Gain Reduction (TD Pocket-Scan only)
Enabled Auto Gain Reduction (AGR) is a feature that is available to the first 20 Pulse
Echo channels. When enabled the currently displayed channel becomes a Master
channel & a Slave channel with the same configuration is automatically created.
Example: If the Master is channel
The channel number of the Slave channel is 1xx, where xx is the channel
1, then the Slave channel will be
number of the Master channel. 101.
If during data collection, data for the Master channel exceeds 96% FSH, the
Slave channel is activated with the specified reduced gain. If the data being
collected by the Master is less than 96%, then the slave channel is not activated.
Gain Reduction The amount of gain reduction to apply to Slave channels.

Channel Page – Probe Category - TOFD

Probe
Wave Type This field allows the selection of an ultrasonic wave type. Compression or Shear. TOFD inspections are normally
performed using compression
waves.
Ultrasonic Velocity The programmed velocity for the selected wave type within the material under
Entered in the Global page.
inspection.
Probe Angle The angle at which the ultrasonic energy is imparted into the test material. Refracted angle.
Delay The time taken for the ultrasound to travel through the wedge. This value is normally calculated
offline by the software.
Offset The distance from a datum on the scanner to the subsequent probes. The datum is usually taken as the
centre of the 1st wedge. The offset
is the measurement from datum to
a subsequent wedge. If the
subsequent wedge is trailing the
datum then the offset is a negative
number.
Separation The distance between the TX and RX transducers. Probe Centre Separation (PCS)
Calc Actual Separation Opens a dialog box that allows the probe separation to be accurately measured. If this procedure is executed
The TOFD transducers must be placed on a calibration block where the material accurately but errors still occur
during analysis, then the material
velocity and thickness are known. Then place the cursors over the lateral wave
velocity is probably incorrect.
and backwall signals on the A-Scan display. This method of measuring the See ‘How to Measure Velocity’ in
separation yields more accurate results in the offline measuring utilities. Appendix A for procedure.
Crystal Diameter Provides a space to enter the probe crystal diameter Used by the auto-reporting facility
and may be left blank
Serial Number Provides a space to enter the probe serial number Used by the auto-reporting facility
and may be left blank
Scan
Scan Type B-Scan (Parallel) / D-Scan (Non-Parallel). This value controls the mathematical In relation to a weld, Non-Parallel is
formulae used during off-line data analysis. when the probes are moved along
the length of the weld (direction of
sound is at 90° to probe
movement) and Parallel is across
the weld (direction of sound is the
same direction as probe movement)
Specimen Depth The depth (thickness) of the material under test.
Focus Depth The required focus depth. This value is used to calculate the required transducer The depth at which the lines of
separation. highest sound pressure (probe
angle) cross.

Focus Depth

Calc Required Determines the optimum probe separation to focus the ultrasonic energy at the
See ‘Calc Required Separation’ in
Separation specified focus depth. Appendix A for procedure.
(Values for Focus Depth and Probe Angle are needed for the calculation)

Channel Page – Probe Category – TOFD – Calculate Actual PCS (Separation)

 Ultrasonic Velocity The programmed velocity for the selected wave type within the material under
Entered in the Global page.
inspection.
Lateral wave Move Cursor 1 (yellow) to the a point on the lateral wave signal The peak (+ or -) of the first
deflection is a convenient point
Backwall Move Cursor 2 (cyan) to the a point on the backwall signal Use the corresponding opposite
phase peak to that chosen for the
lateral wave.
Test Block The wall thickness of the material through which the sound is travelling.
Thickness

Channel Page – Probe Category – TOFD – Calculate Required PCS

Clicking the Calc Required Separation button displays the Result dialogue. The dialogue box displays the Probe Centre Separation (PCS) using
the following formula 2 x (focus depth x Tanθ).

iii. Calculate Required Separation (PCS)

a. On the Probe page, click the Calc Required Separation button.
b. The A-Scan Display Cursors window appears. Move the yellow cursor to a point on the lateral wave signal and the cyan
cursor to the corresponding opposite phase on the backwall signal.
c. Enter the material thickness.
d. Click OK.
e. The correct Probe Centre Separation (PCS) is now displayed in the Separation text box.
f. The following formula is applied:

2 (t × tan θ ) Example:
Focus Depth=25mm
Wedge angle = 60°

2(25 x tan 60)

2(25 x 1.73) = 86.6mm (PCS)
Channel Page – Gates Category - TOFD

TOFD channels only have 1 data collection gate, and are drawn in RED on the A-Scan display.

Start This is the start of the data collection data Measured in microseconds(μs)
Width This is the width of the data collection gate Measured in microseconds(μs)